Tape guide mechanism of magnetic recording reproducing device

ABSTRACT

A tape guide mechanism in a magnetic recording and reproducing apparatus is provided; the magnetic recording and reproducing apparatus includes a movable chassis  1  having a tape guide arm member  30  on which a tape guide  31  is erected and a pair of reels stands thereon and a fixed chassis  2  having a magnetic rotary head thereon, in which the movable chassis  1  moves to one position of said fixed chassis  2  to perform loading and unloading of a cassette and when moves to the other position, tape loading of taking out a magnetic tape from the reel of the loaded cassette to be wound around the magnetic rotary head is performed, wherein after completing the tape loading, the tape guide  31  is fixed to a predetermined position by a guide receiving member  40  that is provided on the fixed chassis  2  to receive the tape guide  31 , and in the middle of the tape guide  31  traveling to said predetermined position, the tape guide arm member  30  is made to move along a groove  2   a  provided in the fixed chassis  2  to determine the position in the chassis plane direction and is guided and moved by the projections  36  provided on the lower surface of the tape guide arm member  30  to determine the position in the height direction.

TECHNICAL FIELD

The present invention relates to a tape guide mechanism of a magneticrecording and reproducing apparatus when, for example, magnetic tape isloaded.

BACKGROUND ART

First, an example of a magnetic recording and reproducing apparatus willbe explained referring to FIGS. 1 and 2.

FIG. 1 shows a linear skating type mechanical deck in a magneticrecording and reproducing apparatus for DV (Digital Video) formatting,for example, and indicates a state in which a movable chassis 1 hasmoved from a fixed chassis 2 to a position where a cassette can bedetached (unloading position). Also, FIG. 2 shows a state in which themovable chassis 1 has slid and moved to a position where magnetic tape(not shown) is loaded onto a magnetic rotary head 8.

In FIG. 1, numeral 1 denotes a U-shaped movable chassis, to which pop-uptype cassette compartments not shown in the figure are attached on bothsides in order for a cassette to be lifted and removed easily, forexample, when the cassette is loaded/unloaded. Further, the movablechassis includes a pair of reel stands 3 and 4 for supplying and takingup tape, and is provided with a reel stand cover plate 5 that coversother mechanical portions than the reel stands 3 and 4, on which atape-end sensor light emitting portion 6, a reel-brake releaseprojection 7 and the like are provided.

Further, as shown in FIG. 2, the magnetic rotary head 8 and a capstan 9are provided on the fixed chassis 2, and on a guide plate 10 around themagnetic rotary head 8, guide-receiving grooves 11 and 12 are provided.The movable chassis 1 slides and moves on the fixed chassis 2 by makingsliding pins 16 and 16 provided on one side surface of the U-shapedportion slide and move in slide grooves 15 and 15 provided on one sidesurface of the fixed chassis 2 by means of a loading gear not shown.

Each of guide rollers 13 b and 13 e on supplying and taking up sidesprovided around the magnetic rotary head 8 moves along the slide grooves11 and 12 respectively, and when tape loading is completed, the rollersare fixed firmly to function as tape guides so that tape runs stablywith respect to the magnetic rotary head 8. Further, on the mechanicaldeck, for example, a tape guide 13 a and a slanted guide 13 c areprovided on the supplying side, and a slanted guide 13 d, a pinch roller9 b, a tape guide 17 and other mechanisms are provided on the taking upside as other guide mechanisms, so that when loading tape, those guidemechanisms move together with the movable chassis 1 and are fixed at apredetermined position for the stable running of the tape.

As shown in FIG. 3, when a cassette 18 is loaded, those guide portionsconstitute a tape path system, in which a magnetic tape 19 pulled outfrom a providing side reel 3 a is helically wound around the magneticrotary head 8 through the tape guide 13 a, a tension regulator 14, theguide roller 13 b, and the slanted guide 13 c; and then the magnetictape is taken up by a taking up side reel 4 a through the slanted guide13 d, the guide roller 13 e, a capstan shaft 9 a, the pinch roller 9 b,and finally the tape guide 17.

As understood from FIG. 3, the tape guide 17 on the taking up sidedirectly functions as the tape guide for the taking up side reel 4 a. Iftaking-up of magnetic tape to a reel is not stably performed, themagnetic tape is contacted with a reel flange to be creased, damaged, ordeteriorated due to the fact that force may not equally be applied tothe whole width of the magnetic tape and so on. Accordingly, in order tomaintain a favorable condition of the magnetic tape 19, it is importantto maintain the height of the tape guide 17 and verticality orpredetermined slant thereof with respect to the movable chassis 1irrelevant to the diameter of the taking up side reel 4 a around whichthe tape is wound, so that the magnetic tape 19 is constantly wound upto be a predetermined height by the taking up side reel stand 4 withouta problem.

FIG. 4 shows an example of a conventional tape guide mechanism and FIG.5 shows the cross section thereof.

On a tape guide arm member 20 constituting the tape guide mechanism, thetape guide 17 is erected and also two shafts are vertically provided, inwhich a rotary fulcrum shaft of the tape guide arm member 20 isconstructed for accurate rotation such that a fulcrum shaft 21 that isone of the shafts vertically provided on the tape guide arm member 20 isinserted to be engaged with a long bearing boss 24 fixed to the movablechassis 1 by caulking. The upper surface of the fulcrum shaft 21 iscovered with the reel stand cover plate 5.

Further, a cam shaft 22 that is the other of the shafts verticallyprovided on the tape guide arm member 20 acts together with the movablechassis 1 and moves in a guide groove 23 of the fixed chassis 2 and in arotation groove 22 a.

The posture (trace) of the tape guide 17 and the tape guide arm member20 in the middle of tape loading or when tape loading is completed isdetermined by the rotation fulcrum shaft 21 of the tape guide arm member20 and the bearing boss 24 of the fixed chassis 2.

Further, the tape guide arm member 20 is forced in the counterclockwisedirection (indicated by an arrow in the drawing) by a spring means suchas a spring not shown. In addition, the height can be adjusted using ascrewdriver or the like for a concave portion 17 a with a groove on topof the tape guide 17. Numeral 17 b denotes a spring means of anauxiliary component for adjusting the height.

As heretofore described, in order for the magnetic tape 19 to travelstably, the tape guide 17 is required to be accurately fixed at apredetermined position on the movable chassis 1, and accurate assemblyis needed to obtain the above required position, when the bearing boss24 is fixed to the movable chassis 1 by caulking, for example.

Further, the tape guide 17 requires accurate height adjustment and abearing component with high accuracy is required at, for example, therotation fulcrum portion of the tape guide arm member 20. Specifically,difference between the outer diameter of the fulcrum shaft 21 and theinner diameter of the fulcrum bearing boss 24 shown in FIG. 5 is madesmall. The difference of dimensions between the fulcrum shaft 21 and thebearing boss 24 when engaged with each other is approximately 0 toseveral ten μm conventionally, and the length for receiving a shaft(fulcrum shaft inserting length) is obtained as long as possible torestrain an inclination, so that the tape guide arm member 20 can bemade to move horizontally, preventing the tape guide 17 erected on theend thereof from falling down.

However, highly sophisticated technology is required to obtain suchaccurate bearing component and engagement accuracy between the outerdiameter of the fulcrum shaft and the inner diameter of the bearingcomponent, which results in the problem of high cost.

Furthermore, to obtain the shaft receiving length as long as possible,there occurs such a problem that no other component can be arranged inthe space in which the bearing moves around, in other words, noflexibility is available for design in the height direction of themechanical deck.

DISCLOSURE OF THE INVENTION

In light of the above problems, the present invention provides a tapeguide mechanism of a magnetic recording and reproducing apparatus, inwhich the structure of a rotation fulcrum portion including a fulcrumshaft of a tape guide arm member, a bearing portion of a movable chassisand the like is simplified, thereby improving the design flexibility inthe height direction.

A first aspect of the present invention is a mechanism in a magneticrecording and reproducing apparatus including a movable chassis on whicha tape guide arm member having a tape guide erected thereon and a pairof reel stands are mounted and a fixed chassis on which a magneticrotary head is mounted, in which when the movable chassis moves to oneposition of the fixed chassis, a cassette is loaded and unloaded andwhen the movable chassis moves to the other position, a tape loadingoperation of extracting magnetic tape from a reel of the cassette loadedto be wound around the magnetic rotary head is performed; wherein aftercompleting the tape loading operation, the tape guide is fixed at apredetermined position by means of a guide receiving member provided onthe fixed chassis to receive the tape guide, and in the middle of themovement of the tape guide to the predetermined position, the tape guidearm member is moved along a groove provided on the fixed chassis todetermine a position in the plane direction and is guided and moved by aprojection provided on the lower surface of the tape guide arm member todetermine a position in the height direction.

A second aspect of the present invention is a mechanism in a magneticrecording and reproducing apparatus according to the first aspect of thepresent invention, in which the tape guide is fixed at the predeterminedposition by means of the guide receiving portion using tension of themagnetic tape loaded onto the tape guide.

According to the above described mechanism, since the posture of thetape guide is fixed when tension of the tape is applied to the tapeguide, accuracy of the posture of the tape guide is not required in themiddle of tape loading, so that the structure of the rotation fulcrumportion of the tape guide arm member can be simplified. Further, withthe simplified structure of the rotation fulcrum portion a bearing neednot be long, so that the flexibility in design in the height directionis improved.

A third aspect of the present invention is a mechanism in a magneticrecording and reproducing apparatus according to the first aspect of thepresent invention, in which the tape guide is fixed at the predeterminedposition by means of the guide receiving portion using tension of themagnetic tape loaded onto the tape guide; the guide receiving portionhas a groove to receive the tape guide arm member and is provided with aprojection on the lower surface thereof; and when tension of themagnetic tape loaded onto the tape guide is applied, the upper surfaceof the tape guide arm member is brought in contact with the projectionon the lower surface of the guide receiving portion to fix the tapeguide to a predetermined position.

According to the above described construction, when tension is appliedto the tape guide, the upper surface of the tape guide arm member isbrought in contact with the projection on the lower surface of the guidereceiving portion to fix the tape guide at a predetermined position, sothat the tape guide can be fixed at the predetermined position with asimplified structure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a magnetic recording andreproducing apparatus when a cassette is loaded/unloaded;

FIG. 2 is a perspective view showing a magnetic recording andreproducing apparatus in the middle of tape loading;

FIG. 3 is a diagram showing a tape path system of a magnetic recordingand reproducing apparatus;

FIG. 4 is a schematic view of a tape guide arm member;

FIG. 5 is a cross sectional view of FIG. 4;

FIG. 6 is a perspective view showing an embodiment of a tape guidemechanism according to the present invention in the middle of tapeloading;

FIG. 7 is a schematic cross-sectional view of FIG. 6;

FIG. 8 is an exploded view dimensionally showing a tape guide armmember, movable chassis and reel stand cover board;

FIG. 9 is a perspective view of a tape guide mechanism showing the statein which tape loading is completed;

FIG. 10A is a top view of FIG. 9 and FIG. 10B is a view shown by A-A ofFIG. 10A;

FIG. 11 is a detailed view of a guide receiving member; and

FIG. 12 is a detailed view of a guide receiving member.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a tape guide mechanism in a magneticrecording and reproducing apparatus of the present invention will bedescribed with reference to drawings. In FIGS. 6 to 12, the samereference numerals are given to portions corresponding to those in FIGS.1 to 5, and detailed explanation will be omitted.

The present invention is a tape guide mechanism in a magnetic recordingand reproducing apparatus, in which when tape loading is completed toload a magnetic tape onto a rotary magnetic head and tape tension isapplied to a tape guide, the tape guide is fixed at a predeterminedposition, so that the tape guide mechanism can be simplified.

FIG. 6 is a perspective view of the tape guide mechanism in the magneticrecording and reproducing apparatus according to the present invention,showing the state in which tape loading is being performed. FIG. 7 is aschematic cross-sectional view of FIG. 6.

In FIG. 6, reference numeral 1 denotes a movable chassis; numeral 2denotes a fixed chassis; numeral 30 denotes a tape guide arm member(hereunder termed an arm) on which an tape guide 31 is erected; andnumeral 32 denotes a reel stand cover plate processed to press the tapeguide arm member 30. Numeral 40 denotes a guide receiving member.

The arm 30 has a cam shaft 22 vertically provided to be inserted into aguide groove of the fixed chassis 2 through a rotation groove 22 aprovided on the movable chassis 1, and the cam shaft 22 moves along aguide receiving groove 2 a provided in the fixed chassis 2 together withmovement of the movable chassis 1. Hereupon, the arm 30 moves along theguide receiving groove 2 a and also rotates in accordance with therotation groove 22 a using a fulcrum shaft 33 described later on erectedon the movable chassis 1 as a rotation fulcrum. Reference numeral 39denotes a spring means, and as shown in FIG. 8, the arm 30 is forced bythe attached spring means 39.

With the above described construction, when loading a tape, the movablechassis 1 slides; the arm 30 travels along a predetermined path; and thetape guide 31 is inserted into the guide receiving groove 42 of theguide receiving portion 41 provided in the guide receiving member 40until a predetermined position.

Further, as shown in FIG. 7, in order for the arm 30 to travel to theguide receiving groove 42 smoothly and to be prevented from greatlyrattling up and down when moving toward the guide receiving groove 42(in the arrow direction), at a position on the lower surface of the arm30 corresponding to the position of the tape guide 31 a hemisphericaljoggle 36 is provided, and the joggle 36 and a touching guide portion 45that has a planarized surface and that is integrally formed with theguide receiving member 40 on a stand 46 are made to slidably move withslightly contacting with each other.

The guide receiving member 40 is made oft for example, an engineeringplastic reinforced against friction, damage or the like and is noteasily worn, so that a predetermined height can be maintained to makethe arm 30 stably travel.

FIG. 8 shows an exploded perspective view of the tape guide arm member,the movable chassis, and the reel stand cover plate. The arm 30 is setfreely movable by means of a rotation fulcrum shaft erected on themovable chassis 1 and a bearing hole of the arm 30 and is forced in thethrust direction.

The fulcrum shaft portion of the movable chassis 1 includes on thechassis: a convex portion 33 a having a larger diameter than a fulcrumshaft, on which a fulcrum shaft 33 of the rotation center of the arm 30is provided, and a retainer shaft 33 b having a diameter smaller thanthat of the fulcrum shaft is erected on the fulcrum shaft 33 providedwith an engaging portion 33 c having a diameter smaller than that of thefulcrum shaft 33 and larger than that of the retainer shaft 33 b on topof the end thereof. Further, a bearing hole 38 having approximately thesame diameter as the fulcrum shaft 33 is bored in the arm 30, and anengaging hole 34 that is made by joining a through hole 34 a, into whichthe engaging portion 33 c is inserted, and on one end of the throughhole 34 a a retaining elliptical hole 34 b having a diameter smallerthan that of the engaging portion 33 c is bored in the reel stand coverplate 32.

First, the cam shaft 22 of the arm 30 is inserted into the rotationgroove 22 a and the engaging portion 33 c of the movable chassis 1 isinserted into the bearing hole 38 of the arm 30 so that the bearing hole38 and the fulcrum shaft 33 are engaged. Subsequently, the engagingportion 33 c projected on the upper surface of the arm 30 is made topass through the through hole 34 a of the engaging hole 34 in the reelstand cover plate 32. Then, the reel stand cover plate 32 is made toslide in the major axis direction of the retaining elliptical hole 34 band as shown in FIG. 6 the retainer shaft 33 b is passed through and fitinto the retaining elliptical hole 34 b so that the arm 30 is forceddown by the reel stand cover plate 32 whose movement in the upwarddirection is restricted by the engaging portion 33 c.

Requiring accuracy on engaging the fulcrum shaft 33 and the bearing hole38 is made different from conventional examples, and is allowed to havea rattle (up to approximately 100 μm, for example); and also the lengthof the bearing is set to have only the plate thickness of the arm 30compared with conventional examples in which the length of the bearingis provided as long as possible, so that the position of the tape guide31 may not be determined by the rotation fulcrum portion.

According to the construction described above, the posture of the tapeguide 31 and arm 30 in the middle of tape loading is determined with thereel stand cover plate 32 regulating the arm 30 in the thrust directionto restrain rattling within a requiring range.

FIG. 9 shows the tape guide mechanism in the magnetic recording andreproducing apparatus of the present invention in the state in whichtape loading is completed; and FIG. 10A shows a top view of FIG. 9 andFIG. 10B shows a view taken by A-A line of FIG. 9.

After traveling to the tape loading position, the arm 30 goes under anapproximately U-shaped guide receiving portion 41, as shown in FIG. 9,and the tape guide 31 reaches the target position in the guide receivinggroove 42, where the magnetic tape run stably. Since a portion around anentrance of the guide receiving portion 41 has been tapered to providethe wider entrance thereof, the tape guide 31 can smoothly enter.

As shown in FIG. 10A, a tape guide support portion 31 a which supportsthe tape guide 31 on the arm 30 has approximately the same diameter asthe width of the guide receiving groove 42, so the rattling of the tapeguide 31 in the direction perpendicular to the lateral direction that isthe direction of travel of the tape guide 31 in the guide receivinggroove 42, can be restrained.

Further, when the arm 30 has traveled to the tape loading position, aconcave portion 43 and an upward supporting portion 44 are provided withthe guide receiving member 40 as shown in detail in FIG. 11 and thejoggle 36 provided on the lower surface of the arm 30 is dropped intothe concave portion 43 provided correspondingly to the guide receivingmember 40 and the lower end portion of the arm 30 is received by theupward supporting portion 44 of the guide receiving member 40.

With the above construction, the joggle 36 is brought into a non-contactstate to be prevented from worn out; and since the joggle 36 is droppedinto the concave portion 43 and the arm 30 is received by the upwardsupporting portion 44, the posture of the arm 30, that is, the postureof the tape guide 31 is maintained at a predetermined height. However,at this stage, the positional accuracy of the tape guide 31 has not yetbeen determined and has not been fixed.

Then, as shown in FIG. 10A, when the tape loading has been completed toload the magnetic tape 19 and tape tension is applied to the tape guide31, the force in the direction indicated by an arrow in FIG. 10B isapplied to the tape guide 31, so that the arm 30 having the abovedescribed rattle is slightly moved upward to come in contact with thelower surface of the guide receiving portion 41.

The above consequence can be obtained only when the arm 30 is allowed tohave an appropriate rattle at the rotation fulcrum portion of the arm30.

FIG. 12 is a perspective view showing the lower portion of the guidereceiving portion 41.

As shown in FIG. 12, projections 41 a and 41 b are provided at portions,which come in contact with the arm 30, on the lower surface of the guidereceiving portion 41 on both sides of the guide receiving groove 42. Theprojections 41 a and 41 b come in contact with the upper surface of thearm 30, as shown in FIG. 10B, to fix the arm 30 and the height,inclination, and the like of the tape guide 31 are determined.

It is desirable that the projections 41 a and 41 b be designed such thatas shown, for example, in FIG. 10B the straight line connecting theprojections 41 a and 41 b is approximately perpendicular to thedirection of tape tension applied to the tape guide 31, when the guidereceiving member 40 is shown from above. Further, each distance from thetape guide 31 to the projections 41 a and 41 b, the height anddimensions of each of the projections, and the like are modified so thatan appropriate position of the tape guide 31 can be obtainedaccordingly.

This embodiment is constructed as described above, and only when thetape tension is applied to the tape guide 31, the position of the tapeguide 31 is determined using that tension, so that the accuracy of theposture of the tape guide 31 in the middle of the tape loading is notrequired and the structure of the tape guide arm member 30 can besimplified.

Further, there is no need to make the bearing of the rotation fulcrumportion of the tape guide arm member 30 long, so that the length thereofcan be made as thin as the plate thickness of the arm member and theflexibility in design in the height direction can be improved.

Furthermore, as explained in this embodiment, in the case where the tapeguide 31 is fixed at the predetermined position and a magnetic tape istaken up by the taking up side reel, the magnetic tape can directly betaken up by the reel without touching the inner guide even with acassette having a guide inside, so that the magnetic tape can beprevented from being worn out and deteriorating.

The structure of the rotation fulcrum portion of the tape guide armmember 30 only needs to be the one in which the posture and path of thetraveling tape guide 31 are determined by a cover plate such as the reelstand cover plate 32 or the like to obtain the similar effectiveness,and such a structure in which, for example, a fulcrum shaft isvertically provided on the side of a tape guide arm member and a bearinghole is provided on the movable chassis side can be considered. Further,although in the above embodiment, the relevant tape guide is the finalguide immediately before taking up the magnetic tape onto a taking upside reel, this embodiment is also applicable to the other guides.

It should be noted that the present invention is not limited to theabove described embodiments and various modifications are attainablewithout departing from the gist thereof.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, when tapetension is applied to the tape guide, the posture of a tape guide isfixed using that tape tension, so that the accuracy of posture of thetape guide is not required in the middle of the tape loading.

Accordingly, the construction of the rotation fulcrum portion of thetape guide arm member can be simplified; and the rotation fulcrumportion can be manufactured easily without using highly accuratetechnology and also, the production cost will be reduced.

Furthermore, with a simplified construction of the rotation fulcrumportion, there is no need to provide a long bearing, so that the designflexibility in the height direction can be improved.

Moreover, according to the present invention, when tension is applied tothe tape guide, the upper surface of the tape guide arm member comes incontact with the projections on the lower surface of the guide receivingportion to fix the tape guide, so that with a simplified construction,the tape guide is fixed to the predetermined position and by slightlyadjusting the projections accordingly, the tape guide can be easilyfixed to the predetermined position.

1. A tape guide mechanism of a magnetic recording and reproducingapparatus that comprises a movable chassis having a tape guide armmember on which a tape guide is erected and a pair of reels standsthereon and a fixed chassis having a magnetic rotary head thereon, inwhich when said movable chassis moves to one position of said fixedchassis, loading and unloading of a cassette is performed and when saidmovable chassis moves to the other position, a magnetic tape is takenout from the reel of the loaded cassette to perform tape loading of saidmagnetic tape being wound around said magnetic rotary head, whereinafter completing the tape loading, said tape guide is fixed to apredetermined position by a guide receiving member having a guidereceiving portion that is provided on said fixed chassis to receive thetape guide, and in the middle of said tape guide traveling to saidpredetermined position, said tape guide arm member is made to move alonga groove provided in said fixed chassis to determine the position in thechassis plane direction and is guided and moved by the projectionsprovided on the lower surface of said tape guide arm member to determinethe position in the height direction.
 2. A tape guide mechanism of amagnetic recording and reproducing apparatus according to claim 1,wherein said tape guide is fixed to a predetermined position by means oftension of the magnetic tape loaded onto said tape guide.
 3. A tapeguide mechanism of a magnetic recording and reproducing apparatusaccording to claim 1, wherein said tape guide is fixed to apredetermined position by means of tension of the magnetic tape loadedonto said tape guide; and said guide receiving portion has a groovereceiving said tape guide arm member and is provided with projections onthe lower surface thereof, and when tension of the magnetic tape loadedonto said tape guide is applied, the upper surface of said tape guidearm member comes in contact with the projections on the lower surface ofsaid guide receiving portion to fix said tape guide to a predeterminedposition.
 4. A tape guide mechanism of a magnetic recording andreproducing apparatus according to claim 1, wherein on said movablechassis a convex portion having a diameter larger than that of a fulcrumshaft is provided, on the convex portion the fulcrum shaft is erected, aretainer shaft having a diameter smaller than that of the fulcrum shaftis provided and a engaging portion having a diameter smaller than thatof the fulcrum shaft and larger than that of the retainer shaft isjoined; a bearing hole having approximately the same diameter as that ofthe fulcrum shaft is bored in said tape guide arm member; a plate havingan engaging hole including an insertion hole where the engaging portionis inserted and a retainer hole that is provided at an end of theinsertion hole to be joined and that has a diameter smaller than that ofthe insertion hole; the engaging portion of said movable chassis isinserted through a bearing hole of said tape guide arm member so thatthe bearing hole is engaged with the fulcrum shaft, the engaging portionprotruding on the upper surface of said tape guide arm member isinserted into the insertion hole of the engaging portion of said plate,and said plate is slid in the major axis direction of the retainerelliptical hole to insert and fix the retainer shaft into the retainerelliptical hole; and said tape arm guide arm member is pressed by saidplate whose movement in the upward direction is restrained by saidengaging portion.